The yeast Candida bogoriensis and a Torulopsis species produce large quantities of an extracellular glycolipid which is a sophoroside derivative of hydroxy fatty acids. This study involves the isolation and purification of enzymes participating in the synthesis and metabolism of these glycolipids, characterization of these enzymes and their interaction with their lipid substrates, and attempts to discover the function of these glycolipids in the physiology of the yeasts.